What has the ATTRACT seed funding enabled you to do so far?
The ATTRACT funding has enabled substantial progress in the development of ULTRARAM™ memories for Internet of Things (IoT) sensors. Prior to the start of the project we had demonstrated room-temperature operation of individual, low-voltage, non-volatile memory cells. We have now processed our first 4-bit memory arrays on GaAs substrates, and made good progress in implementing the memory on Si.
What challenges have you faced so far?
There have been substantial technical challenges. The fabrication of 4-bit arrays is by far the most complex work that has ever been attempted in our clean rooms, involving, for example, making direct contact to a layer that is 12 nm thick, fabrication of word and bit lines across samples, deposition of high-quality isolation layers. For implementation on Si, after several months of effort we had to abandon our original plan of GaSb on GaAs on Ge on Si, which combined A known industry process of Ge on Si and our existing GaAs on GaSb technology, and work on a new route: GaSb on Si with AlSb seed. Successful production of our memory arrays also relies on a large variety of state-of-the-art equipment, with downtime of any one of these causing significant disruption.
Where does your ATTRACT journey go from here?
Within the time frame of the project we still need fabricate a couple more iterations of individual devices and 4-bit arrays on GaAs. Growth of the memory layers on Si needs further optimisation in order to fabricate 4-bit arrays on Si before the final ATTRACT event in Brussels in September. Beyond that, the next stage will be 8×8 = 64-bit arrays on Si, ideally before the end of 2020, and then a 1-Mbit demonstrator array with fully integrated III-V CMOS logic, in 2023 or 2024. At that stage the technology will be ready for integration into IoT sensors, and large-scale manufacture for a non-volatile RAM can be developed.
Sum up in two sentences the advantages of the ATTRACT Programme over other research funding schemes.
The streamlined administration and flexible nature of budget spend that allows us to concentrate on the research. The strong emphasis on commercialisation, including additional activities such as the ESADE Introductory Crash Course in Entrepreneurship.